2017-04-25

Blueberry Flea Beetle

Photo Credit: Hillier Lab

The blueberry flea beetle (Altica sylvia Malloch)has been reported in all Atlantic Provinces and in the Eastern US and frequently arises in lowbush blueberry fields (has also been found in highbush blueberry). When the level of an infestation is high enough it can cause severe damage to foliage leading to crop loss. The larvae which feed primarily on the growing foliage (but also on the developing buds) cause the most damage. However if an adult population is big enough in numbers it too can cause significant damage to the leaves. See picture to the right for typical feeding damage on the leaves.

The practice of mowing the fields has led to larval infestations in sprout and crop fields. When burned every 2 years the blueberry flea beetle is rarely a problem in fields as the eggs are destroyed with a deep enough burn. 

The adult insect will jump when disturbed and are therefore called flea beetle. The insect goes through four life stages: egg, grub (larva), pupa, and adult. It spends the winter in the egg stage (1 mm long, oval shaped and orange-yellow). The eggs are laid near the base of the plant or in the fallen leaves, singly. In spring the eggs hatch over a 2 to 3 week period with peak populations occurring from late May to mid to late-June. Then they gradually decline.

The pupa (oval shape, orange and 4-5 mm long) can be found up to 12 mm into the soil. The adult flea beetle is oval shaped, shiny, 5 mm long and has a coppery bronze colour. They can be collected from early July to early September, sometimes into October; adults do not survive the winter. 

The current method of monitoringBlueberry flea beetle populations is sweeping the foliage in sprout and crop field sections with a sweep net, which has to be done regularly and is very labour intensive. 

Information was provided by the Hillier Lab and partially excerpted from NB AAF.

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